A Fuzzy Logic Approach to Case Matching and Retrieval Suitable to SQL Implementation

The aim of this paper is to formally introduce a fuzzy logic based notion of acceptance and similarity among case features, for case matching and retrieval. In particular, we present an approach where local acceptance relative to a feature can be expressed through fuzzy distributions on its domain, abstracting the actual values to linguistic terms. Furthermore, global acceptance is completely grounded on fuzzy logic, by means of the usual combinations of local distributions through specific defined norms. We propose a retrieval architecture, based on the above notions and implemented through a fuzzy extension of SQL.